Answer:
-4.67
Step-by-step explanation:
first find f^-1(x)
let f(x)=y
y=3x+2
3x=y-2
x=y-2/3
Therefore f^-1(x)=x-2/3
Now f^-1(-12)=-12-2/3
=-14/3
=-4.67
A = L * W
A = 80
L = 5W
80 = W(5W)
80 = 5W^2
80/5 = W^2
16 = W^2
sqrt 16 = W
4 = W <=== width is 4 ft
L = 5W
L = 5(4)
L = 20 <=== length is 20 ft
(amount raised) = $2 × (number of classmates)
We know that the 15% of missing pencils is equal to 9
we can use this formula
9/x = 15/100
Then cross multiply
15x = 900
x = 60
There were orignally 60 pencils